1. Field of the Invention
The present invention relates to a method and apparatus for preparing spare tools for a machine tool of the type wherein a number of spare tools associated with some of primary tools, along with the primary tools, are stored in a tool magazine each for use on a tool spindle of the machine tool in place of an associated one of the primary tools when the same reaches the end of its life.
2. Description of the Prior Art
In a known machine tool with a spare tool change function, a tool magazine stores a number of spare tools respectively associated with some of primary tools, in addition to the primary tools. When one of the primary tools reaches the end of its life, a tool exchanger attaches an associated one of the spare tools on a tool spindle, in place of the life-expired primary tool. It is therefore possible for the machine tool to automatically perform the change-over from a life-expired primary tool to an associated spare tool without discontinuing the automatic continuous operation of the machine tool.
The machine tool, however, requires that spare tools corresponding in number to all of primary tools which are liable to be subjected to wear or damage, be stored in the tool magazine at a time. This disadvantageously results in an increased capacity of the tool magazine for the spare tool change function. Particularly, this drawback is unavoidable in the case that a primary tool needs not only a first spare tool, but also a secondary spare tool.